How to check internet connection in Swift 3 or Swift 4?

Question

I have tried checking internet connection in Swift 3 but the code is not working for me.

 class func isConnectedToNetwork() -> Bool {

    var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
    zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
    zeroAddress.sin_family = sa_family_t(AF_INET)

    let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
      SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0)).takeRetainedValue()
    }

    var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: UInt32(0))
    if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == 0 {
      return false
    }

    let isReachable = (flags & UInt32(kSCNetworkFlagsReachable)) != 0
    let needsConnection = (flags & UInt32(kSCNetworkFlagsConnectionRequired)) != 0

    return (isReachable && !needsConnection) ? true : false
  }

I have also imported the SystemConfiguration framework. Please suggest how to check.

Solution

Latest swift3 code

Here The easiest way to check for internet connectivity is to use the iOS reachability api. check this bellow link and download add reachability file to your projects .you must and should be added systemconfiguration framework is added to the project

 [1]: https://github.com/ashleymills/Reachability.swift/tree/feature/ios10

After finishing above work just write this code for checking networking connection.here i am writing some alert message also.

    func networkStatusChanged(_ notification: Notification) {
    let userInfo = (notification as NSNotification).userInfo
    print(userInfo!)
}
func interNetChecking( )   {
    let status = Reach().connectionStatus()


    switch status {
    case .unknown, .offline:

        let alert = UIAlertController(title: "Check", message: "Internet Connection is Required at first time running the app to load images and videos ", preferredStyle: UIAlertControllerStyle.alert)
        alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.default, handler: nil))

        DispatchQueue.main.async(execute: {
            self.present(alert, animated: true, completion: nil)
        })


        print("Not connected")
    case .online(.wwan):
        print("Connected via WWAN")
    case .online(.wiFi):
        print("Connected via WiFi")
    }


}

Comments

[Arildo Junior]

If you are connected to a wi-fi but not able to connect to the internet (open a google page) still it returns true for reachable. It's wrong.

[mxlhz]

Don't forget to call reachabilityManager.startListening() or the listener won't be called at all. Here is an interesting link as there are things to consider on a simulator with this code: github.com/Alamofire/Alamofire/issues/2275